dream super bike

[fossyant]

Hang on, you really haven't got this ?

Wind resistance is a big problem, the Lightning (aircraft) solved its rubbish aerodynamics by overpowering (with enough power you can make a brick fly)

So where are you going to get this additional power from ? It's driven by a person.

 

[Licramite]

just watched the video of 126mph on the record breakers, now hook that up to a 100tooth chainring , the pedal resistance wasn,t that great as you could see.
and I,m only aiming at 1/4 of that speed - the secret I think is to overpower and aim at poor effeciency
(solar panels are the least effecient solar energy producer - but the most consistantly effecient system over wind/wave power - as an example)

 

[Licramite]

Gearing - and l love the the smilee verse the brick wall.

 

[Rob3rt]

Gearing - and l love the the smilee verse the brick wall.

Are you a bit simple?

 

[black'n'yellow]

just watched the video of 126mph on the record breakers, now hook that up to a 100tooth chainring , the pedal resistance wasn,t that great as you could see.
and I,m only aiming at 1/4 of that speed - the secret I think is to overpower and aim at poor effeciency
(solar panels are the least effecient solar energy producer - but the most consistantly effecient system over wind/wave power - as an example)

A quarter of 126mph is 31mph - which is a speed eminently attainable by a reasonably fit person on a 'regular' bicycle.

 

[dan_bo]

.........but in reality probably made me look like an ape in a fat suit attempting coitus with an unwieldy and unwilling ancient bit of mathematics apparatus......

Superb line.

 

[Licramite]

yes - but then on a 40mile ride why do I only acheive an average speed of 10-12mph.
its a consistant speed of 30mph is what I,m aiming at.
(this is only a design exercise at present but an interesting problem)

as for being a bit thick
Pythagerus didn,t say give me a month in the gym and I will move the world - he said give me a fulcrum and a long enough lever and I will move the world - the extra power comes from extra gearing - the power input stays the same.

 

[Andrew_Culture]

Superb line.

Accurate too!

 

[black'n'yellow]

yes - but then on a 40mile ride why do I only acheive an average speed of 10-12mph. .

because you are not fit enough.

 

[Andrew_Culture]

How many teeth is on that thing. ?
.

145ish teeth, and the radius is about 5ft

 

[Rob3rt]

yes - but then on a 40mile ride why do I only acheive an average speed of 10-12mph.
its a consistant speed of 30mph is what I,m aiming at.
(this is only a design exercise at present but an interesting problem)

as for being a bit thick
Pythagerus didn,t say give me a month in the gym and I will move the world - he said give me a fulcrum and a long enough lever and I will move the world - the extra power comes from extra gearing - the power input stays the same.

Because you are not very fit! If you want to go 30mph, train hard, train smart, eat properly! There are plenty of people who average ~30mph over 25 mile's in TT's.

As for the latter, nice quote, but you are missing the point!

 

[jonny jeez]

I,m looking to build a bike , something that will do 40-50mph.

if gears and ratios was the answer, I'm pretty sure the tour teams would have realised this and created a the wundergear by now.

As fossy says, its the engine that does the work. A massive gear would be impossible to turn (even if you worked up to it). if it weren't the top guys would be turning them now.

 

[jonny jeez]

Pythagerus didn,t say give me a month in the gym and I will move the world - he said give me a fulcrum and a long enough lever and I will move the world - the extra power comes from extra gearing - the power input stays the same.

true, physics does work that way. But you have it reversed. If you want to move a massive object you need a massive lever. If you wanted to turn a massive gear, you would need an equally massive lever (leg) to do so.

Your gears are already set to shift massive objects (like Pythagerus's lever) but they work in the other direction, the smaller the cog the higher the leverage (hill climb anyone) so, this large cog idea would work in principle but you would then need a pully system or huge lever to turn the massive cog.

hence the double cogs that you mention you don't understand. The second cog is a pully that generates a gear sufficient to turn the 1st

 

[Zakalwe]

Why do you think that after 100+ years of bicycle evolution we've settled on a 50ish tooth chainrings? Thousands of people have tried to find the optimum gearing for maximum efficiency and that's what's been most successful. There's no UCI rule as far as I know on toothing, sometimes you see compacts on a hilly ride, sometimes 56t on a TT. If there was something to gain from a 70t ring people would be riding them, but they don't.

 

[fossyant]

This thread is absolutely hillarious. I blame Wiggle .

OK enough of being polite. The original poster is wasting his time 'designing' a new bike with a mahoosive gear if he's not fit enough to power a conventional bike at more than 10-12 mph over 40 miles.

I would suggest you start riding your bike more - this works mirracles. Try riding 100 miles at about 20 mph - then you'd be considered as reasonably fit cyclist - takes lots and lots of training. It's like an inverse pyramid - lots of quality miles to get that little peak of performance.

Please listen to the folk here, they are some very experienced cyclists. You are either a spotty teenage boffin who knows nothing about bikes/aerodynamics or dillusional.

Get training, and you can compete in the National Time Trials - those folk can do a sustained 30 mph on a TT bike, with conventional gearing. Even HPV's (bikes built into a giant egg shape ) don't have gears that huge !